This invention relates to a rheometer and to a method of measuring the rheological properties of a sample, particularly a sample of bitumous material.
Rheometers are well known instruments for measuring the rheological properties of samples, normally placed between the facing surfaces of upper and lower probes or plates one of which is driven relative to the other. The rheometer includes measuring means, such as strain gauges and position gauges for measuring the movement strains induced between the probes in accordance with the properties of the sample. The rheometer is connected to computer means for analysing these measurements so that a computerised control functions to enable the rapid determination of the tested materials properties over a broad range of possible testing frequencies and temperatures. The operating software allows the rheometer to be programmed easily for different test procedures.
Measurable visco-elastic parameters include the modulus, which is the ratio of the applied torque to resultant strain, and the phase angle, which is defined as the phase shift between the stress and strain waves. Presentation of other related visco-elastic parameters such as storage and loss modulus is also possible.